The 8-year-old Guatemalan boy who died in U.S. custody this week had the flu, according to autopsy results announced by New Mexico authorities. An official cause of death for Felipe Gomez Alonzo has not been confirmed. The New Mexico Office of the Medical Investigator said in a statement Thursday that more tests need to be done before a cause of death can be determined. The boy was taken to the hospital after a border agent noticed signs of illness, and medical staff first diagnosed him with a common cold. Authorities say Alonzo died at a New Mexico hospital on Christmas Eve after suffering coughing, vomiting, and a fever.

“Results of nasal and lung swabs have tested positive for influenza B,” the New Mexico Office of the Medical Investigator said in a statement. “As always, the office is focused on our mission of properly investigating deaths to serve the living... We extend our condolences to his family and loved ones.” Jakelin Caal, a 7-year-old girl also from Guatemala, died in U.S. custody on Dec. 8. Their deaths remain under investigation.